A Discovery of Witches, published in 2011, is a historical-fantasy novel and the inaugural work of American author Deborah Harkness. The narrative centers on Diana Bishop, a professor of the history of science at Yale University, who comes to terms with her magical heritage after discovering a long-lost manuscript. This revelation leads her into a forbidden romance with the captivating vampire, Matthew Clairmont.

The novel was initially released in hardcover on February 8, 2011, by Penguin Books, quickly achieving the status of a New York Times Best Seller. It has since been made available in paperback and as an ebook, and has been translated into over 36 languages.